Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds useful behavioral context: results are 'newest first' and include status, recipient, dates, line items, totals, document links, plus page and perPage. It does not mention auth needs, rate limits, or pagination edge cases, but its added value over the annotations is solid.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences with no waste. The primary purpose, return content, and sorting rule are front-loaded, and the alternative-tool routing follows immediately. Every sentence earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description appropriately explains the return shape: invoices with status, recipient, dates, line items, totals, document links, plus page and perPage. Combined with the 100% schema coverage and complete annotations, an agent has enough information to select and invoke the tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents all five parameters in detail, including the important search caveat. The description adds no parameter-specific meaning beyond what the schema provides. Baseline 3 applies when the schema carries the parameter burden.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb and resource: 'List a company's sales invoices from Osome invoicing, newest first.' It also distinguishes this tool from siblings by naming what it is not for: 'get-overdue-invoices or get-invoice-pending-summary for receivables from the accounting ledger.' An agent can tell it apart from those tools without opening a schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It explicitly routes the agent to alternatives: 'Use get-overdue-invoices or get-invoice-pending-summary for receivables from the accounting ledger, and preview-invoice to read one invoice.' This gives both when-to-use and when-not-to-use guidance with named siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.